/* ========================================================================
 * PlantUML : a free UML diagram generator
 * ========================================================================
 *
 * (C) Copyright 2009-2017, Arnaud Roques
 *
 * Project Info:  http://plantuml.com
 * 
 * This file is part of PlantUML.
 *
 * PlantUML is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * PlantUML distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
 * License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * Original Author:  Arnaud Roques
 * 
 * Revision $Revision: 5079 $
 *
 */
package net.sourceforge.plantuml.hector2.layering;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import net.sourceforge.plantuml.cucadiagram.IEntity;
import net.sourceforge.plantuml.hector2.continuity.Skeleton;

public class LayerFactory {

	public List<Layer> getLayers(Skeleton skeleton) {
		skeleton = skeleton.removeCycle();
		skeleton.computeLayers();
		final List<Layer> result = new ArrayList<Layer>();
		for (IEntity ent : skeleton.entities()) {
			ensureLayer(result, ent.getHectorLayer());
		}
		for (IEntity ent : skeleton.entities()) {
			final int layer = ent.getHectorLayer();
			result.get(layer).add(ent);
		}
		return Collections.unmodifiableList(result);
	}

	private void ensureLayer(List<Layer> result, int layerToAdd) {
		while (result.size() <= layerToAdd) {
			result.add(new Layer(result.size()));
		}

	}
}
